MEASURES on DESIGN DRAWINGS

Post 602 by Gautam Shah 

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These are rules per ISO, and also better methods of writing measurements on DESIGN RELATED DRAWINGS. These apply to manual drawings and also CAD representations.

All decimal numbers must be preceded by a zero if no other digit exists. e.g. 0.121 (and not as .121 )

No thousand or hundred markers are to be used, e.g. 1000 (and not 1,000), but where large number of digits are involved a blank or space (equal to 1 digit or not less than ½ digit in width) may be used as a separator, in place of a marker. However, where only four digits are used no space as a separator need be provided. e.g. 100 000, 10 000 or 1000 (but not 1 00 000 or 1 000).

▪ For Length units recognized measures are km / m / mm which may if at all required must be in small letters. For example architectural plans have nearly all measures in mm, so the mention of mm should be avoided. However, in the same drawing if weight or volume or such other measures are to be indicated, then identifiers for such units may be indicated.

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Architectural drawings nominally have dimensions of maximum 5 digits (for mm ) unless a detail requires indicating a fraction of a millimeter, signifying measures up to 99999 mm or 99.999 mts (-but unit identifiers are not to be used). Plans larger then 99mts sizes are considered of Map Category.

▪ Full names of units even when these are named after a person, are written in small letters: ampere, volt etc., with the exception W for watt and J for Joule.

▪ For liquid measure (Litre) however lt may be written as Lt (to differentiate between 1 and l ).

▪ Plurals of measures need not be used. (kms, mts, kgs).

Point or Full stop for abbreviation may not be used, for example as in m.g. or ml.

▪ Where cubic or square measures are to be shown: 3m3 = will mean three cubic metres and not 33 i.e. 3 x 3 x 3 = 27cmt.

▪ Following common units are acceptable

Length  mm m  km (all 1000 factored=103)

Weight  gm  kg  mt or t (all 1000 factored=103)

Liquid  mlt  Lt  klt (all 1000 factored=103).

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Where traditionally only one unit is accepted, and if there are no chances of ambiguity, the measure nomenclature (mm, km, gm etc.) may not be mentioned. (E.g. cloth width = 1.200). If in one sheet of drawing (or a document) only one scale and one mode of measure are used, the nomenclature may be mentioned as a general instruction for the drawing.

Where drawings or details are likely to be graphically reduced or enlarged in processing / copying, a graphical scale preferably showing 100 mm bar may be shown. If 100 mm size is not suitable due to micro reduction or macro enlargement, suitable multiples of 100 mm for upwards scaling and 10x fractions of 100 mm for downwards scaling maybe used.

Formwork-trad-beam

MEASUREMENTS ON DESIGN DRAWINGS

When both mt & mm are used on drawings, it will be less confusing if the dimensions are always written to three places of decimals, i.e. 3.450. No unit symbol need be shown unless a lesser number of decimal places are used; i.e. 3.450 or 3.45 m and under some circumstances 3.5 m, are all correct. Of the options, 3450 and 3.450 both are preferred. Where no ambiguity can arise, symbols may be discarded, according to following rules:

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▪ Whole numbers indicate mm

▪ Decimated fractions to three palaces of decimals indicate m (and also by implication, mm)

All other dimensions or measures must be followed by the unit symbol.

▪ Where dimensions refer to different types of measures (lengths, weights, temperature etc.), preferably all units should be indicated or all units other than the major one should be indicated.

▪ Main dimensions and the tolerance (fitments, limits, margins etc.) etc. should be in the same unit system.

▪ Where main dimensions are accompanied by + or – range, both should be in the same unit.

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All architectural drawings follow ISO modular preferences and these are as follows:

ISO’s Four Preferences for Modular Coordination:

       First Preference            30 cm or 300 mm = 12″

      Second Preference      10 cm or 100 mm = 4″

      Third Preference           5 cm or 50 mm = 2″

      Fourth Preference        2.5 cm or 25 mm = 1″

First Preference is favoured by the building materials’ industry. Plywoods and other wood products are available in modules of 300 such as 600, 900, 1200, 1800, 2400 etc. Large buildings are designed with 300 as the modular measure. But, for smaller spaces such as Bedrooms, toilets, second preference of 100 is used as a module.

Second Preference is considered to be the most appropriate one for Building components and Planning. Glazed Tiles are available in multiples of 100 mm, with sizes like 100 x 200, 200 x 200, 200 x 300 etc., and also in sizes such as 150 x 150, 150 x 200 etc. as a carry over from the old system. Fabrics have widths of 600, 900, 1000, 1200, 1800 etc. When we order Windows or Doors the width x height are measured in 100 mm increments.

Third and Fourth Preferences are more preferred for objects smaller then 300 sizes. These preferences are not to be used for basic object sizes of more than 300, unless there are strong economic or functional reasons for doing differently.

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MODULAR MEASURES

MODULAR MEASURES

Post 427 ⇒   by Gautam Shah 

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There was a time when all things were measured with comparison to the body and figured with numbers. The numbers were fingers such as Five, Ten or Twenty, or hex multipliers like Six or Dozen, and easily divisible Octet series of 4, 8, 16, 32. Different regions followed own measure numbering system. Varied measure numbering systems created problems like lot recognition and commercial pricing for the lot. To compound the problem, the monetary unit fractioning was equally varied.

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The French revolution helped select a ‘scientific’ digital system. It offered 7-10 fractions @10X. The system created utter confusion as to who (which trade) should follow which of the units. The problems of preferring few select units increased manifold, when other countries adopted the Metric digital format but with different set of units. As countries (mainly Spanish colonies in Latin Americas) began to use Metric digital format, with different preferred units, the need for rational and common units became pronounced.

Bronze wool weight of 14 lb (6.4 kg) (1550–1600) stamped with the Royal coat of arms. (Victoria and Albert Museum) Wikipedia Image by David Jackson

There were few other problems with digital units @10X . The digital (time) hour of 1/10 or 1/20 part of the day, or minute to second relationship (@10X) was not acceptable to sailors and astrologers, using compass fractionated into 360 degrees, arcs, minutes and seconds. This had to be rolled back to the original method.

A measuring for volumes of liquids in units of cups, fluid ounces, and milliliters.

Before and soon after World War II, several conferences helped resolve the issue of preferred units of measurements. SI (Système International d’Unités) first recognized, Three units 1000 factored apart, in every series (e.g. km-mt-mm). These were either too large or small for practical applications. A widely spaced measurement system was not amenable to unit formation for processes like planning, design, production, transportation, fabrication or execution, etc. So ISO (International Standards Organization) devised a practical modular system of dimensions known as ISO Modular Preferences. Most National Standards (including Indian Standards) are recommending and enforcing the same for various products and processes.

Imperial measurement standards At Greenwich

Before these were recognized and accepted, there were practical units of measure modulations. For examples plywood and other sheet materials were produced in 4 / 5 Ft widths. Tiles were available in 6 /8/12 inch squares. Foot (12 inches ) was the most popular module and was accommodated in the new order. This was done for wider acceptance and to achieve a gradual changeover.

Module – grid based plan

ISO’s Four Preferences for Modular Coordination:

FIRST PREFERENCE (300 mm = 12 inches) This is favoured by the building materials’ industry. Plywoods and other sheet products are available in modules of 300 such as 600, 900, 1200, 1800, 2400 etc. Large buildings are designed with 300 as the module. But, for smaller spaces such as Bedrooms, toilets, second preference of 100 is used as a module.

SECOND PREFERENCE (100 mm = 4 inches ) This is considered to be appropriate one for Building components and Planning. Glazed Tiles are available in multiples of 100 mm, with sizes like 100 x 200, 200 x 200, 200 x 300 etc., and also in sizes such as 150 x 150, 150 x 200 etc. as a carry over from the old system. Fabrics have widths of 600, 900, 1000, 1200, 1800 etc. When we order Windows or Doors the width x height are measured in 100 mm increments.

THIRD PREFERENCE (50 mm = 2 inches) and FOURTH PREFERENCE (25 mm = 1 inch), are suggested for objects smaller then 300 sizes. Though these modules are not to be used for basic object sizes of more than 300, unless there are strong economic or functional reasons for doing differently.

Tatami as the module for planning of Japanese houses

There are many products where smaller modulation or variations are desirable such as Garments and Shoes. ISO Modular Preferences, do not consider the variations in naturally available materials. Furniture, fittings and fixtures designed with ergonomic profile or serving anthropometric, inconsistencies have no specific accommodation in this system.

Grid for ceiling

ISO is a modular system to form a grid or matrix for macro planning and in that sense takes a superior position. Components and parts are expected to fit in the system. As a result, work-sizes of components and assemblies should be determined by taking into account space for joint and allowance for tolerances.

Geodesic Hex grid Climatron Missouri Botanical Gardens

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IMPLICATIONS OF DIMENSIONAL COORDINATION # 1

Post 421  by Gautam Shah 

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During pre-medieval periods trade with distanced lands was managed by shippers and caravan masters. These agents conducted the business through the holistic (piece or item) value of the goods, rather then through its measures. This system of commerce changed, in medieval age when many European nations established their own trading posts in colonies across Asia, Africa and American continents. The colonists bought goods at the trading posts, transited and sold in their own country. This was mainly conducted in measure traditions of their mother lands.

Weeks_Edwin_Lord_Arrival_of_a_Caravan_Outside_The_City_of_Morocco

Caravan outside Morocco

The European nations, each had distinctive measure systems. The measure systems of lengths, weights or volumes, each had incomparable units, and their subfractions were illogical. These problems were already realized, but now with increased colonial trade, as it caused vast problems. The current political leaderships (Royals) were not capable of solving it.

Sea Trade in Europe

With the onset of Industrial age, the trade, transit and conversion of raw materials, became closely interrelated. Natural raw materials passed through several processes, spread across many nations, to become vast variety of finished products. During the conversion the applicable measure systems also changed. For example, Cotton bought on volume basis, was converted into fabric -sold by lengths, and dresses -sold by numbers. Metal ore is mined in volumetric measure, transported by its weight measure, bought for its yield rate value, refined into ingots for weight measures, rolled into metal sections to be used for their strength aspect.

Colonial post at Salem India

● The transition to common measures systems developed at many fronts. Arabic numerals (actually of Indian origin) became common in Europe, and began to replace the Roman numbers, during the late Middle Ages (about 1500). This made decimal system possible (after Simon Stevin, a Flemish mathematician, in 1585, showed in his book ‘De Thiende’, how fractions could be expressed in decimals.) Vicar, Gabriel Mouton, St. Paul’s Church, Lyons, France, proposed a decimal system of measurement in 1670. Bishop of Autun, also known as Talleyrand was the political sponsor of weights and measures reforms in the French Revolutionary National Assembly. 1790, in the midst of the French Revolution, the National Assembly of France requested the French Academy of Sciences to “deduce an invariable standard for all the measures. Larger and smaller multiples of each unit were to be created by multiplying or dividing the basic units by 10 and its powers. France made its use compulsory in 1840.

10X divisioned clock of French Metric system

Raw materials and Finished products’ are misleading terms for goods. A finished product is a raw material for some other process. Raw materials procured in a linear, square, volumetric, weight or liquid measures get processed into a different ‘measure’ entity. For products transiting from one measure phase to another, a persistent dimensioning system is very advantageous. Consistency of dimensions allows use of standard tools, equipments, plants and technologies. The dimensional consistency, if properly recognized and supported, can rationalize the conversion processes, storage, handling, and waste management.

Ship Batavia –International trade

Steam Engine and Ship

In the Post Industrial Revolution period, trade and industry all over the world recognized the need for a Universal Dimensioning Discipline. At that time better coordination was also required for conversion and transmission from old measurement systems to any new system of measurements. First worldwide understanding emerged in the adoption of SI as the Universal Measure System.

Kuantan Port Yard Container modulated units

Organisation internationale de normalization or International Organization for Standardization would have different acronyms in different languages. Its founders decided to give it a short, all-purpose name. They chose ISO derived from the Greek isos, meaning equal. ISO is a voluntary, democratic and non governmental organization for International Cooperation for Standardization. SI = Systeme Internationale stand for Universal Measure System and it is now accepted by nearly all countries of the world.

Universally agreed parts

SI Recognized Measures: The SI system recognizes three sets of measures in each of the major categories. There is a 1000-factored gradation.

            The ISO Recognized Measures are:

            Length:           mm     mt        km

            Weight:          mg      kg        T

            Volume          ml        Lt         kl

All other measures such as centimeter cm or gram gm are not to be used.

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MEASURING UP

Post 394 – by Gautam Shah 

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We define objects and happenings primarily with measures. Measures when combined with time show the changes that occur in things. Measures are very important in recording and recreating events and happenings, through their start, duration, termination, and the rate at which these actualize.

Roman Weight of stone

Measures define things in terms of lengths, areas, volumes or weights. Measures offer comparative scaling for sensorial perceptions, define load and work capacities, and determine reach and occupancy in space.

Human body limb sizes, reach and capacities -Basis of early measure systems

There was a time, when things were measured in terms of body sizes and capacities. Long distances were measured for the travel time required, like in lunch breaks or night halts. Short distances were measured in arm lengths, cubit (the length from the elbow to the tip of the middle finger), or foot steps of the traveller. Still smaller sizes were measured with the palm, breadth of a hand, length of a finger, or width of a thumb. Finer widths were measured in terms barley grains. Volumetric measures were the holding capacity of a limb like pinch or palm. Weights were measured in grains, fruits or stone pebbles, or in terms of carrying or displacement capacity of a person or animal, such as head load, a cart load, horsepower.

A common unit of weight in Ethiopia was the load – a simple measure of the amount carried by a beast of burden such as a camel

Measures are comparative facts. A thing to be measured is compared (equated) with something similar, familiar, or with a thing that has already been calibrated. Measures based on body sizes or capacities had many individual, racial and regional variations. Other standards were changeable and perishable. These units of measures were not replicable (recreate-able) and comparable. There was no hierarchical relationship between large and small measures. The conversion from one unit size to another was, often very illogical.

During the Middle Ages, major cities had their own set of measures and the public availability of these standards allowed visiting merchants to comply with local regulations. The official Viennese ell length standards for verifying the measure of different types of cloth sold are embedded in the cathedral wall, to the left of the main entrance. The linen ell, also called Viennese yard, (89.6 centimeters (35.3 in)) and the drapery ell (77.6 centimeters (30.6 in)) length standards consist of two iron bars.

The differences were somehow equated in barter trading between neighbours. But the same process was proving to be very difficult for trade with far of regions and transacted in some form of monetary units. There was an acute need for some common measure system. Gradually each trading block concurred to a common tradition of nominal measurements. Many different localized or regional measure systems flourished. Conversion between adjunct systems was not very difficult, as the trade occurred comparatively in small lots. Conversion of measures with adjoining trade regions was managed by intermediaries like brokers, caravan masters and shippers. The inconsistencies of the measure conversions were partly solved with monetary pricing replacing the bartered trading. The monetary trade system came to replace the barter trading, where only ‘universally’ measured goods were evaluated in a primary standard like gold.

Caravan Traders exchanging goods

At places things were transformed to different measure systems. Like grains were measured by volume (bushel) than by weight. Textiles were traded by weight than by lengths. Liquids (oils) were sold by volume. Yet, measure systems were mutually incompatible. To compound the problem each system had a different scale of sub fractioning. The complexity multiplied when differently fractionated measure units were equated with equally varied units and sub fractions of monetary units.

Measurement of mass – the gravitational force on the measure and is balanced against the gravitational force on the weights.

This problem of differential fractioning of measures and money was sought to be solved during the French Revolution. During the French Revolution (1870), the National Assembly of France asked French Academy of Sciences to formulate a scientific and rational measure system. Such a system was expected to be:

1 neutral and universal,

2 replicable anytime and anywhere,

3 to have decimal multiples,

4 to follow common prefixes,

5 be practical and simple to use.

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MEASURES

Folding Ruler

Measures are the basis of all exchanges and for checking the efficiencies. Measures identify the quantum of work and the productivity in time scale. Measures are based on body sizes or capacities, but these have many racial and regional variations. It is possible to equate out such differences in a personal exchange or barter trade between neighbours. But, the same proves to be very difficult for trade with far-off regions. Intermediary like, brokers, caravan masters and shippers facilitated trade with other regions and also made large profits through Conversion of measures. Some form of common measure system is required to communicate the achievements of human endeavours.

The inconsistencies of the measure conversions are solved partly, when monetary pricing replaced the bartered trading. Monetary valuation provides a common ground for comparison. World wide, the trading blocks had to concur to a common set of Nominal measurements.

All measure systems such as weights, lengths, volumes were once mutually incompatible, as each had a different scale of sub fractioning. The problems multiplied when measures were equated with equally varied units and sub fractions of monetary units. This was sought to be solved during the French Revolution.

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